Flame retention nozzle



D 60. 26, 1944. w FERGUSON 2,365,945

FLAME RETENTION NOZZLE Filed March 7, 1942 Patentecl Dec. 26, 1944 pairs!) STATES ATEN psi-"ms Q essence V I nLmu-nammron' nozzm- William .Feryguson, Thiladelphia, Qua, iassignor to .NationaLAiroil Burne'rCompany, Incorporated, a corporation of Delaware H r flplilication Marh 7, 1942, Serial K03 133348 'slclaims. (c1..15s-- 1L0a)'-* The invention relates toimprovements in flame retention nozzles, especially of the "common and well known type, such "as :isshown in my pending "application "Serial No. 424961 filed Dec.- '30, 1941, which matured into *Patent No. 2,333,531; dated lNovemberz, 1943.

The -object is to provide an air-cooled nozzle.

Because ofits construction and operation it does not require theme of heatwesisting alloy, which is expensive and -ciiiiic1ilt to procure at the presenttime.

An object therefore is to provide a flame re- .tention'no'zzl'e WhiChpQI-lnits the use of cast iron merely by way of example, suitable means for the embodiment of my invention:

Fig. 1 is a View partly in elevation and in part perspective, of the device in accordance with my invention.

Fig. 2 is a perspective view of the same, looking into the discharge end.

Fig. 3 is a section on the line 3-3 of Fig. 2.

Fig. 4 is a simple elevation.

Fig. 5 is a sectional detail on an enlarged scale.

Similar numerals refer to similar parts throughout the several views.

As shown, especially in Figs. 1, 3 and 4, this nozzle-has a cylindrical formation 9. It is provided with spaced apart parallel reinforcing ribs ID. The parts of the cylindrical formation between the ribs and between the middle part of the cylinder and its outer end, are formed to extend inwardly to provide a tapered or contracted discharge passag I I. The four wall sections I4 forming depressions (looking toward the outside) are all inclined to each other, with the result that the discharge passage through the nozzle is first contracted as shown at II, and then with a flaring outermost part I! for the discharge of air-gas mixture.

Passages or channels I3 are arranged in the projecting portions I4 (looking from within) of the side walls of the nozzle, as shown in Figs. 3 and 5. These passages have inlet openings I5 into the main chamber I for receiving the combustible mixture and-discharge openings I6 in the face I1 of the flaring portion of the nozzle. These discharge openings or ignition ports I6 are preferably provided in spaced relationship around the inclined surface of said flaring face H.

The said outer face of the nozzle, which is exposed to the heat of conibustion, 'is protected against 'heat deterioration by a facing l l, which is (if a refractory insulating plastic. 'The said ignition'por ts' W6 of this "facing register with the channels or passages I3. These ports are pro-- vided with recessed gas itip's' I9, which *are inserted at a suitable angle to'dire'ct the flame jets against the :main volume "of the combustible mixture passing through the nozzle. This-design of the ignition jet formation -prevents "the overh'eatin g and burnin'g 0f the :casting, which takes placewith the lcu'stomalryretention nozz'l'e. 1 llhese recessed :g'as tips ialso allow df a greater turn-down without flash back.

A raw gas pilot 20, similar to any one of the discharge openings I6, delivering from an independent raw gas supply, is also made an integral part of the nozzle, not depending upon the flow of mixture through the main passage of the nozzle. It is safe, effective and an inexpensive device for quickly lighting the main gas burner. This pilot port 20 is connected with a passage 2|, (Fig. 3) similar to the other passages I3, except that the inlet. I5 maybe closed and an inlet provided for receiving raw gas from the out-- side of the nozzle through a pipe 22, having an independent control by means of the regulating valve 23.

For example-Fig. 5 shows a screw plug I2 inserted in a branch of passage I3 or 2I, while inlet I5 is open to receive combustion mixture from the main chamber 1. In such case the pilot 20 functions as any of the other pilots.

When, on the other hand, it is desired to 0011'.- nect port 20 with a raw gas supply, the screw plug I2 is removed and replaced by the end of raw-gas supply pipe 22.

Any number of such pilots may be used.

Nozzles are used for delivering a mixture of primary air and gas to the furnace for burning without flash back or loss of ignition. They are designed to take the place of flame retention nozzles now in general use.

These nozzles are designed to and do reduce the cost of nozzle maintenance and replacements where a high furnace temperature, a plus furnace pressure, or preheated air is used. They have proved especially economical in replacements.

Unlike the ordinary flame retention nozzles for severe service, this nozzle is notmade of a heatresisting alloy that is so expensive at this time. The design of the nozzle, as above stated, permits use of cast-iron and yet insures a relatively long life.

As shown in Fig. 5, a special form of jet producing body is provided for the ignition ports; this body cooperatin with the refractory flaring face I I. -It comprises an elongated cylindrical formation l9, open at the discharge end and provided with a jet orifice 24 at its inner or intake end. The outer or discharge end of i9 is preferably flush with the refractory face IT. The gas is projected through the small jet orifice 24, through the cylindrical chamber [9, so that the gas, or gas and air mixture will burn at the open end of said cylinder. It will thus be seen that the wall of the cylinder 19 and the refractory face the other end being tapered to form a contracted discharge passage, a flaring formation for receiving the discharge from said passage, said chambered body also having channels in its wall leading from the tapered area of said chamber to said flaring formation, one at least of said channels having a port intermediate its two ends which may be connected with a source of raw gas.

2. A flame retention nozzle com-prising a cylindrical chambered body having one end formed to connect with a source of combustible mixture,

' the other end being tapered to form a contracted l7 cooperate in protecting the orifice 24 from the heat of combustion. Such an arrangement has been found extremely effective in preventing overheating and clogging of said orifice 24.

The formation of the channels l3 has important advantages. It tends to retard the flow of combustible mixture, and contributes to the prevention of overheating the nozzle. It facilitates the forming of the channel in the burner body, and it provides simple and effective means for shifting the connection with the main chamber, to connection with a source of raw gas and vice versa.

In other words, the production of these channels l3 in an integral flame retention nozzle, as shown in Figs. 3 and 5, is believed to be a very distinct advance in the art.

What I claim is:

1. A flame retention nozzle comprising a cylindrical chambered body having one end formed to connect with a source of combustible mixture.

discharge passage, a flaring formation for receiving the discharge from said passage, said body also having channels leading from the tapered .area of said chamber to said flaring formation,

said chambered body provided with parallel spaced apart reinforcing ribs positioned between the said converging and flaring walls and providing bodies for receiving the said channels.

3. A gas nozzle comprising a cylindrical chambered body. having one end formed to connect with a source of combustible mixture, the other end being tapered to form a contracted discharge passage, and a flaring formation for receivin the discharge from said passage, the surface of said flaring formation being provided with an annular recess extending from near the inner and outer margins of said flaring formation and a refractory seated in said recess, providing a smooth continuous frusto-conical surface between said margins. v

WILLIAM FERGUSON. 

